<?php
// +----------------------------------------------------------------------
// | TOPThink [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2010 http://topthink.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: 麦当苗儿 <zuojiazi@vip.qq.com> <http://www.zjzit.cn>
// +----------------------------------------------------------------------
// | GIF.class.php 2013-03-09
// +----------------------------------------------------------------------
namespace Think\Image\Driver;

class GIF
{

    /**
     * GIF帧列表
     * 
     * @var array
     */
    private $frames = array();

    /**
     * 每帧等待时间列表
     * 
     * @var array
     */
    private $delays = array();

    /**
     * 构造方法，用于解码GIF图片
     * 
     * @param string $src
     *            GIF图片数据
     * @param string $mod
     *            图片数据类型
     */
    public function __construct($src = null, $mod = 'url')
    {
        if (! is_null($src)) {
            if ('url' == $mod && is_file($src)) {
                $src = file_get_contents($src);
            }
            
            /* 解码GIF图片 */
            try {
                $de = new GIFDecoder($src);
                $this->frames = $de->GIFGetFrames();
                $this->delays = $de->GIFGetDelays();
            } catch (\Exception $e) {
                E("解码GIF图片出错");
            }
        }
    }

    /**
     * 设置或获取当前帧的数据
     * 
     * @param string $stream
     *            二进制数据流
     * @return boolean 获取到的数据
     */
    public function image($stream = null)
    {
        if (is_null($stream)) {
            $current = current($this->frames);
            return false === $current ? reset($this->frames) : $current;
        } else {
            $this->frames[key($this->frames)] = $stream;
        }
    }

    /**
     * 将当前帧移动到下一帧
     * 
     * @return string 当前帧数据
     */
    public function nextImage()
    {
        return next($this->frames);
    }

    /**
     * 编码并保存当前GIF图片
     * 
     * @param string $gifname
     *            图片名称
     */
    public function save($gifname)
    {
        $gif = new GIFEncoder($this->frames, $this->delays, 0, 2, 0, 0, 0, 'bin');
        file_put_contents($gifname, $gif->GetAnimation());
    }
}

/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFEncoder Version 2.0 by László Zsidi, http://gifs.hu
 * ::
 * :: This class is a rewritten 'GifMerge.class.php' version.
 * ::
 * :: Modification:
 * :: - Simplified and easy code,
 * :: - Ultra fast encoding,
 * :: - Built-in errors,
 * :: - Stable working
 * ::
 * ::
 * :: Updated at 2007. 02. 13. '00.05.AM'
 * ::
 * ::
 * ::
 * :: Try on-line GIFBuilder Form demo based on GIFEncoder.
 * ::
 * :: http://gifs.hu/phpclasses/demos/GifBuilder/
 * ::
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 */
class GIFEncoder
{

    private $GIF = "GIF89a";
 /* GIF header 6 bytes */
    private $VER = "GIFEncoder V2.05";
 /* Encoder version */
    private $BUF = Array();

    private $LOP = 0;

    private $DIS = 2;

    private $COL = - 1;

    private $IMG = - 1;

    private $ERR = Array(
        'ERR00' => "Does not supported function for only one image!",
        'ERR01' => "Source is not a GIF image!",
        'ERR02' => "Unintelligible flag ",
        'ERR03' => "Does not make animation from animated GIF source"
    );

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFEncoder...
     * ::
     */
    public function __construct($GIF_src, $GIF_dly, $GIF_lop, $GIF_dis, $GIF_red, $GIF_grn, $GIF_blu, $GIF_mod)
    {
        if (! is_array($GIF_src) && ! is_array($GIF_dly)) {
            printf("%s: %s", $this->VER, $this->ERR['ERR00']);
            exit(0);
        }
        $this->LOP = ($GIF_lop > - 1) ? $GIF_lop : 0;
        $this->DIS = ($GIF_dis > - 1) ? (($GIF_dis < 3) ? $GIF_dis : 3) : 2;
        $this->COL = ($GIF_red > - 1 && $GIF_grn > - 1 && $GIF_blu > - 1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : - 1;
        
        for ($i = 0; $i < count($GIF_src); $i ++) {
            if (strToLower($GIF_mod) == "url") {
                $this->BUF[] = fread(fopen($GIF_src[$i], "rb"), filesize($GIF_src[$i]));
            } else 
                if (strToLower($GIF_mod) == "bin") {
                    $this->BUF[] = $GIF_src[$i];
                } else {
                    printf("%s: %s ( %s )!", $this->VER, $this->ERR['ERR02'], $GIF_mod);
                    exit(0);
                }
            if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF[$i], 0, 6) != "GIF89a") {
                printf("%s: %d %s", $this->VER, $i, $this->ERR['ERR01']);
                exit(0);
            }
            for ($j = (13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07))), $k = TRUE; $k; $j ++) {
                switch ($this->BUF[$i]{$j}) {
                    case "!":
                        if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE") {
                            printf("%s: %s ( %s source )!", $this->VER, $this->ERR['ERR03'], ($i + 1));
                            exit(0);
                        }
                        break;
                    case ";":
                        $k = FALSE;
                        break;
                }
            }
        }
        $this->GIFAddHeader();
        for ($i = 0; $i < count($this->BUF); $i ++) {
            $this->GIFAddFrames($i, $GIF_dly[$i]);
        }
        $this->GIFAddFooter();
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFAddHeader...
     * ::
     */
    private function GIFAddHeader()
    {
        $cmap = 0;
        
        if (ord($this->BUF[0]{10}) & 0x80) {
            $cmap = 3 * (2 << (ord($this->BUF[0]{10}) & 0x07));
            
            $this->GIF .= substr($this->BUF[0], 6, 7);
            $this->GIF .= substr($this->BUF[0], 13, $cmap);
            $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . $this->GIFWord($this->LOP) . "\0";
        }
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFAddFrames...
     * ::
     */
    private function GIFAddFrames($i, $d)
    {
        $Locals_str = 13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07));
        
        $Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1;
        $Locals_tmp = substr($this->BUF[$i], $Locals_str, $Locals_end);
        
        $Global_len = 2 << (ord($this->BUF[0]{10}) & 0x07);
        $Locals_len = 2 << (ord($this->BUF[$i]{10}) & 0x07);
        
        $Global_rgb = substr($this->BUF[0], 13, 3 * (2 << (ord($this->BUF[0]{10}) & 0x07)));
        $Locals_rgb = substr($this->BUF[$i], 13, 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07)));
        
        $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 0) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "\x0\x0";
        
        if ($this->COL > - 1 && ord($this->BUF[$i]{10}) & 0x80) {
            for ($j = 0; $j < (2 << (ord($this->BUF[$i]{10}) & 0x07)); $j ++) {
                if (ord($Locals_rgb{3 * $j + 0}) == (($this->COL >> 16) & 0xFF) && ord($Locals_rgb{3 * $j + 1}) == (($this->COL >> 8) & 0xFF) && ord($Locals_rgb{3 * $j + 2}) == (($this->COL >> 0) & 0xFF)) {
                    $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 1) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . chr($j) . "\x0";
                    break;
                }
            }
        }
        switch ($Locals_tmp{0}) {
            case "!":
                $Locals_img = substr($Locals_tmp, 8, 10);
                $Locals_tmp = substr($Locals_tmp, 18, strlen($Locals_tmp) - 18);
                break;
            case ",":
                $Locals_img = substr($Locals_tmp, 0, 10);
                $Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);
                break;
        }
        if (ord($this->BUF[$i]{10}) & 0x80 && $this->IMG > - 1) {
            if ($Global_len == $Locals_len) {
                if ($this->GIFBlockCompare($Global_rgb, $Locals_rgb, $Global_len)) {
                    $this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
                } else {
                    $byte = ord($Locals_img{9});
                    $byte |= 0x80;
                    $byte &= 0xF8;
                    $byte |= (ord($this->BUF[0]{10}) & 0x07);
                    $Locals_img{9} = chr($byte);
                    $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
                }
            } else {
                $byte = ord($Locals_img{9});
                $byte |= 0x80;
                $byte &= 0xF8;
                $byte |= (ord($this->BUF[$i]{10}) & 0x07);
                $Locals_img{9} = chr($byte);
                $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
            }
        } else {
            $this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
        }
        $this->IMG = 1;
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFAddFooter...
     * ::
     */
    private function GIFAddFooter()
    {
        $this->GIF .= ";";
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFBlockCompare...
     * ::
     */
    private function GIFBlockCompare($GlobalBlock, $LocalBlock, $Len)
    {
        for ($i = 0; $i < $Len; $i ++) {
            if ($GlobalBlock{3 * $i + 0} != $LocalBlock{3 * $i + 0} || $GlobalBlock{3 * $i + 1} != $LocalBlock{3 * $i + 1} || $GlobalBlock{3 * $i + 2} != $LocalBlock{3 * $i + 2}) {
                return (0);
            }
        }
        
        return (1);
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFWord...
     * ::
     */
    private function GIFWord($int)
    {
        return (chr($int & 0xFF) . chr(($int >> 8) & 0xFF));
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GetAnimation...
     * ::
     */
    public function GetAnimation()
    {
        return ($this->GIF);
    }
}

/*
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 * ::
 * :: GIFDecoder Version 2.0 by László Zsidi, http://gifs.hu
 * ::
 * :: Created at 2007. 02. 01. '07.47.AM'
 * ::
 * ::
 * ::
 * ::
 * :: Try on-line GIFBuilder Form demo based on GIFDecoder.
 * ::
 * :: http://gifs.hu/phpclasses/demos/GifBuilder/
 * ::
 * :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 */
class GIFDecoder
{

    private $GIF_buffer = Array();

    private $GIF_arrays = Array();

    private $GIF_delays = Array();

    private $GIF_stream = "";

    private $GIF_string = "";

    private $GIF_bfseek = 0;

    private $GIF_screen = Array();

    private $GIF_global = Array();

    private $GIF_sorted;

    private $GIF_colorS;

    private $GIF_colorC;

    private $GIF_colorF;

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFDecoder ( $GIF_pointer )
     * ::
     */
    public function __construct($GIF_pointer)
    {
        $this->GIF_stream = $GIF_pointer;
        
        $this->GIFGetByte(6); // GIF89a
        $this->GIFGetByte(7); // Logical Screen Descriptor
        
        $this->GIF_screen = $this->GIF_buffer;
        $this->GIF_colorF = $this->GIF_buffer[4] & 0x80 ? 1 : 0;
        $this->GIF_sorted = $this->GIF_buffer[4] & 0x08 ? 1 : 0;
        $this->GIF_colorC = $this->GIF_buffer[4] & 0x07;
        $this->GIF_colorS = 2 << $this->GIF_colorC;
        
        if ($this->GIF_colorF == 1) {
            $this->GIFGetByte(3 * $this->GIF_colorS);
            $this->GIF_global = $this->GIF_buffer;
        }
        /*
         *
         * 05.06.2007.
         * Made a little modification
         *
         *
         * - for ( $cycle = 1; $cycle; ) {
         * + if ( GIFDecoder::GIFGetByte ( 1 ) ) {
         * - switch ( $this->GIF_buffer [ 0 ] ) {
         * - case 0x21:
         * - GIFDecoder::GIFReadExtensions ( );
         * - break;
         * - case 0x2C:
         * - GIFDecoder::GIFReadDescriptor ( );
         * - break;
         * - case 0x3B:
         * - $cycle = 0;
         * - break;
         * - }
         * - }
         * + else {
         * + $cycle = 0;
         * + }
         * - }
         */
        for ($cycle = 1; $cycle;) {
            if ($this->GIFGetByte(1)) {
                switch ($this->GIF_buffer[0]) {
                    case 0x21:
                        $this->GIFReadExtensions();
                        break;
                    case 0x2C:
                        $this->GIFReadDescriptor();
                        break;
                    case 0x3B:
                        $cycle = 0;
                        break;
                }
            } else {
                $cycle = 0;
            }
        }
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFReadExtension ( )
     * ::
     */
    private function GIFReadExtensions()
    {
        $this->GIFGetByte(1);
        for (;;) {
            $this->GIFGetByte(1);
            if (($u = $this->GIF_buffer[0]) == 0x00) {
                break;
            }
            $this->GIFGetByte($u);
            /*
             * 07.05.2007.
             * Implemented a new line for a new function
             * to determine the originaly delays between
             * frames.
             *
             */
            if ($u == 4) {
                $this->GIF_delays[] = ($this->GIF_buffer[1] | $this->GIF_buffer[2] << 8);
            }
        }
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFReadExtension ( )
     * ::
     */
    private function GIFReadDescriptor()
    {
        $GIF_screen = Array();
        
        $this->GIFGetByte(9);
        $GIF_screen = $this->GIF_buffer;
        $GIF_colorF = $this->GIF_buffer[8] & 0x80 ? 1 : 0;
        if ($GIF_colorF) {
            $GIF_code = $this->GIF_buffer[8] & 0x07;
            $GIF_sort = $this->GIF_buffer[8] & 0x20 ? 1 : 0;
        } else {
            $GIF_code = $this->GIF_colorC;
            $GIF_sort = $this->GIF_sorted;
        }
        $GIF_size = 2 << $GIF_code;
        $this->GIF_screen[4] &= 0x70;
        $this->GIF_screen[4] |= 0x80;
        $this->GIF_screen[4] |= $GIF_code;
        if ($GIF_sort) {
            $this->GIF_screen[4] |= 0x08;
        }
        $this->GIF_string = "GIF87a";
        $this->GIFPutByte($this->GIF_screen);
        if ($GIF_colorF == 1) {
            $this->GIFGetByte(3 * $GIF_size);
            $this->GIFPutByte($this->GIF_buffer);
        } else {
            $this->GIFPutByte($this->GIF_global);
        }
        $this->GIF_string .= chr(0x2C);
        $GIF_screen[8] &= 0x40;
        $this->GIFPutByte($GIF_screen);
        $this->GIFGetByte(1);
        $this->GIFPutByte($this->GIF_buffer);
        for (;;) {
            $this->GIFGetByte(1);
            $this->GIFPutByte($this->GIF_buffer);
            if (($u = $this->GIF_buffer[0]) == 0x00) {
                break;
            }
            $this->GIFGetByte($u);
            $this->GIFPutByte($this->GIF_buffer);
        }
        $this->GIF_string .= chr(0x3B);
        /*
         * Add frames into $GIF_stream array...
         */
        $this->GIF_arrays[] = $this->GIF_string;
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFGetByte ( $len )
     * ::
     */
    
    /*
     *
     * 05.06.2007.
     * Made a little modification
     *
     *
     * - function GIFGetByte ( $len ) {
     * - $this->GIF_buffer = Array ( );
     * -
     * - for ( $i = 0; $i < $len; $i++ ) {
     * + if ( $this->GIF_bfseek > strlen ( $this->GIF_stream ) ) {
     * + return 0;
     * + }
     * - $this->GIF_buffer [ ] = ord ( $this->GIF_stream { $this->GIF_bfseek++ } );
     * - }
     * + return 1;
     * - }
     */
    private function GIFGetByte($len)
    {
        $this->GIF_buffer = Array();
        
        for ($i = 0; $i < $len; $i ++) {
            if ($this->GIF_bfseek > strlen($this->GIF_stream)) {
                return 0;
            }
            $this->GIF_buffer[] = ord($this->GIF_stream{$this->GIF_bfseek ++});
        }
        return 1;
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFPutByte ( $bytes )
     * ::
     */
    private function GIFPutByte($bytes)
    {
        for ($i = 0; $i < count($bytes); $i ++) {
            $this->GIF_string .= chr($bytes[$i]);
        }
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: PUBLIC FUNCTIONS
     * ::
     * ::
     * :: GIFGetFrames ( )
     * ::
     */
    public function GIFGetFrames()
    {
        return ($this->GIF_arrays);
    }

    /*
     * :::::::::::::::::::::::::::::::::::::::::::::::::::
     * ::
     * :: GIFGetDelays ( )
     * ::
     */
    public function GIFGetDelays()
    {
        return ($this->GIF_delays);
    }
}
